It is a well-known technique in the art of bipolar circuitry to use a resistor with one terminal connected to the base of a bipolar transistor and the other terminal connected to the emitter of the bipolar transistor to provide higher speed operation of the transistor, particularly in digital applications. When a bipolar transistor is turned on (i.e., when bias current is applied to the base and a low conductivity is present between the collector and the emitter), the forward bias on the base emitter junction behaves as a capacitive load. When it is desired to turn the transistor off (i.e., to create a high conductivity state between the emitter and the collector), forward bias current to the base is removed. However, a certain amount of forward bias charge remains in the base to emitter junction until this charge is discharged. A resistor is placed between the base and emitter to allow a path for this discharge to speed the process of turning off of the transistor.
In integrated circuitry, resistors are a very difficult component to make. Simple use of resistive elements provides a structure which is much larger than transistors themselves. To this end, circuit designers have used other transistors to form resistor-like devices in integrated circuitry. However, even these structures require the addition of the whole area of an additional transistor to provide the appropriate discharging capability for the base to emitter junction.